On Monday came a deal with organized labor that food service, restaurant, concession and other arena workers could unionize, which came shortly before a hearing at the board’s land use committee on the arena design.

In a town where waterfront development is almost always contentious and organized labor holds considerable political sway, it’s easy to understand the strategy of getting unions publicly behind you.

“Many of us often talk about labor peace,” Mayor Ed Lee said at the second arena-labor signing ceremony in his office in a week. “In these days, I am more talking about labor confidence and labor happiness. Because ‘labor peace’ often says there’s a dispute going on. Here we’re going way beyond.”

The deal between the basketball franchise and Unite Here Local 2, which represents food service and hotel employees, also allows the roughly 500 current workers at Oracle Arena in Oakland to keep their jobs and transfer to the new San Francisco venue when it opens, slated for the start of the 2017-18 NBA season.

The agreement requires any operation inside the arena with 15 or more employees to allow workers to choose who represents them. That would also apply to a proposed hotel directly across the Embarcadero from the pier and to food and beverage businesses with 45 or more employees operating elsewhere on the 15-acre project site.

The arena development is projected to create 1,700 net new ongoing jobs, although officials couldn’t provide an estimate of exactly how many of those would be union.

“It’s … about building communities,” Mike Casey, president of the San Francisco Labor Council, said before signing the deal, “and we build communities by establishing jobs that provide people with a living wage.”

But there is still plenty of opposition to the project, primarily from nearby residents concerned about crowds, traffic and views who also contend the approval process is moving too quickly.

Supervisor Scott Wiener, while supportive of the arena, warned that Muni’s subway capacity is inadequate to meet current demand, and the situation would worsen with people flocking to a new 17,500-seat arena with about 200 events a year.

Other supervisors, while complimentary of the design, which includes seven acres of public open space on Piers 30-32, suggested additions to those areas, like a public basketball court and a playground.